Method and device for detecting crystal direction of silicon slice

Abstract

The invention provides a method and device for detecting the crystal direction of a silicon slice. The method includes the steps that an image pickup device which comprises a light source and one or more image pickup probes rotates in different angular directions to irradiate the silicon slice, corresponding reflection strength is acquired, and a reflection curve of interested crystal particles in a polar coordinate system is drawn; pixel brightness extreme values are marked in the reflection curve, the normal directions of three or more faces of regular octahedrons of the crystal particles <111> are determined, then normal vectors of all the regular octahedrons are calculated, and therefore the crystal directions of the interested crystal particles can be calculated.

Description

technical field [0001] The invention relates to a detection method and a detection device for silicon wafer crystal orientation. Background technique [0002] The grain size of solar ingot polycrystalline silicon wafers is generally about 1cm, and the number of single silicon wafer grains is more than 500. Due to the different crystal orientations among the crystal grains, the influence on the subsequent battery process is also different. For example, <100> crystal orientation can obtain pyramid texture with high light-harvesting effect by alkali texturing, while <111> crystal orientation can only obtain texture by acid texturing or other isotropic texturing methods. Different crystal grains have different crystal orientations, and different crystal orientations have different texture characteristics, which in turn produce different surface recombination rates, which affect the performance parameters of the final battery. Therefore, the accurate detection and e...

AI Technical Summary

Problems solved by technology

[0004] 1) X-ray diffraction technology (X-Ray diffraction, referred to as XRD), its beam spot diameter is generally several mm, and can only measure the crystal orientation of a single grain of a silicon wafer at a time, which is costly and time-consuming , completely unable to meet the needs of the industry

[0005] 2) Electron backscattered selective diffraction (EBSD for short), which is suitable for micro-area crystal orientation detection, can be used for surface scanning, and its spatial resolution can reach 0.1 μm, but the measurement range is only limited to how many cm 2 , not suitable for rapid characterization of full-scale silicon wafers

The rotary table reflection method disclosed in CN103151283A already has sufficient industrial applicability, but the applicant further found the following improvements in the process of implementing it: the calculation method is a method of comparing with the standard crystal orientation, and the theoretical accuracy limited

Images